estuaries
greengabbro | March 7, 2008
Picture courtesy reader Martin. Or maybe Martin doesn't actually read this blog, and it's just Wren. Anyway, thanks, Wren and Martin!
Today's rock is a geopuzzle: What's up with these ridges? How did they get there, and what determines their size?
I don't actually know the answer, so this is the best hint you're going to get out of me.